package com.justnow.offer;



import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;

/**
 * @author justnow
 * Created on 2020-09-14
 * Description
 */
public class Solution47 {
    public List<List<Integer>> level2(TreeNode root) {
        List<List<Integer>> list = new ArrayList<>();
        Queue<TreeNode> queue = new LinkedList<>();
        if (root != null) {
            queue.add(root);
        }
        int time = 1;
        while (!queue.isEmpty()) {
            LinkedList<Integer> temp = new LinkedList<>();
            for (int i = queue.size(); i > 0; i--) {
                TreeNode node = queue.poll();
                if (time % 2 == 0) {
                    temp.addFirst(node.val);
                } else {
                    temp.addLast(node.val);
                }
                if (node.left != null) queue.add(node.left);
                if (node.right != null) queue.add(node.right);
            }
            list.add(temp);
            time++;
        }
        return list;
    }

    public static void main(String[] args) {
        TreeNode node1 = new TreeNode(1);
        TreeNode node2 = new TreeNode(2);
        TreeNode node3 = new TreeNode(3);
        TreeNode node4 = new TreeNode(4);
        TreeNode node5 = new TreeNode(5);
        TreeNode node6 = new TreeNode(6);
        TreeNode node7 = new TreeNode(7);

        node1.left = node2;
        node1.right = node3;
        node2.left = node4;
        node2.right = node5;
        node3.left = node6;
        node3.right = node7;

        Solution47 solution45 = new Solution47();
        List<List<Integer>> ints = solution45.level2(node1);
        for (List<Integer> list : ints) {
            System.out.println(list);
        }
    }
}
